In the description that follows, the term “escalator” is inteded to include moving walks, and the term “step” shall also include pallets of moving walks, irrespective of whether the latter terms are specifically maintained.
The steps of a conventional escalator are fastened to two transporting chains together to form an endless circulating step-loop which, at each end of the escalator, runs over a pair of transporting-chain wheels. One of the pairs of transporting-chain wheels belongs to a drive station and drives and reverses the step-loop, and the other pair of chain wheels being part of a step-loop reversing station. The individual steps of the step-loop are each equipped with two front guide rollers and two rear guide rollers on which the steps are guided in a position-dependent defined position by means of guiderails and cams or reversing curves which are primarily fastened to the supporting construction of the escalator.
At the upper stairhead of an escalator or moving walk with a balustrade a main shaft is built in. The main shaft is borne in the truss at its left and right sides. The manner of being borne must be executed as simply as possible since, should bearing damage occur, the main shaft must be dismounted from the escalator.
The main shaft drives the steps or which are guided on the rails. To make driving the steps easier, the main drive is, for example, executed as a hollow-shaft construction. In this hollow-shaft construction, the main shaft consists of a stationary axle which is held in bearings in the truss of the escalator. Around this axle a rotating hollow shaft is mounted which is connected to the axle through rolling-contact bearings. This hollow axle rotates and carries the step-loop or pallet-loop. The axle which carries the hollow shaft is typically fastened tightly to the truss with screws.
The described embodiment has the disadvantage that in the case of, for example, a defective rolling-contact bearing, extensive dismantling and installation work is necessary, since the rolling-contact bearings can only be dismounted and remounted by moving them lengthwise to the end of the axle. To pull the rolling-contact bearings and the hollow shaft out, the stationary axle must be dismounted from the truss, which is laborious and time-consuming, especially in consideration of the weight of such an axle (500 kg). The call for short interruption times for correction of every type of possible defect cannot be met with such a construction.
Mounting of the shaft takes place when the escalator is installed. Dismounting of the shaft takes place when the escalator is maintained. Installation and maintenance are two different steps in the value chain.
The purpose of the present invention is to avoid the aforesaid disadvantage in an escalator or moving walk, i.e. to enable replacement of a defective rolling-contact bearing or of any other component in substantially less time.
A further purpose of the present invention is to enable simpler and faster mounting and dismounting of the shaft of an escalator or moving walk, using as few components as possible, thereby bringing about a reduction in installation costs.